<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        #result {
            width: 300px;
            height: 100px;
            border: solid 1px #903;
          }
    </style>
</head>
<body>
    <button>发送请求</button>
    <button>取消请求</button>
    <script>
        //获取元素对象
            const btns = document.querySelectorAll('button');
            let x = null;
            btns[0].onclick = function(){
                x = new XMLHttpRequest();
                x.open("GET","http://127.0.0.1:8000/delay");
                x.send();
            }
            //abort 取消请求
            btns[1].onclick = function(){
                x.abort();
            }
    </script>
</body>
</html>